Re: a question on DMA and remapping

[Alan Cox]

> Generalising the existing code to cover more cases isn't a bad thing
> to do.  Others might be able to use it, and they surely won't be able
> to use any cloned-and-owned swiotlb.c.

If you look on the kernel list there has also been some discussion and
work recently towards removing a lot of the duplication between the
iommu devices.

I think really you need to be an actual iommu instance because in
reality you are. Trying to fudge it any other way breaks the moment
someone tries to do a device to device DMA transfer because your
bus/phys mapping seen from your device and the bus/phys mapping seen
from another device into your device do not match as I understand it.

Alan
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